12721 ÷ 4 = 3180 R1
We're going to perform division on 12721 with 4 as the divisor.

Step 1:
4 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 1 to get 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 4

Step 2:
4 goes into 12 3 times with a remainder of 0.
Write down 3 as next digit of of the result. 
Result so far: 3
Subtract 12 from 12 to get 0.
Bring next digit (7) of the dividend behind the 0 and repeat the process: 7 / 4

Step 3:
4 goes into 7 1 times with a remainder of 3.
Write down 1 as next digit of of the result. 
Result so far: 31
Subtract 4 from 7 to get 3.
Bring next digit (2) of the dividend behind the 3 and repeat the process: 32 / 4

Step 4:
4 goes into 32 8 times with a remainder of 0.
Write down 8 as next digit of of the result. 
Result so far: 318
Subtract 32 from 32 to get 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 4

Step 5:
4 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 3180
Subtract 0 from 1 to get 1.

The final result is 3180 with a remainder of 1.